Gbeeitt smith



(No Model.)

G.- SMITH.

DIPLEX 0R QUADRUPLEX TELEGRAPH. No. 297,540. Patented Apr. 22, 1884.

' INVENTOR WITNESSES Gerzilt Smifia,

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U ITED STATES PATENT @rricn.

GERRITT SMITH, OF ASTORIA, NEWV YORK.

DIPLEX OR QUADRUPLEX TELEGRAPH.

SPECIFICATION forming part of Letters Patent. No. 297,540, dated April 22, 1884.

Application filed July 7, 1883.

To all whom it may concern.-

Be it known that 1, GERRITT SMITH, a citizen of the United States, residing at Astoria, in the county of Queens and State of New York, have invented certain new and useful Improvements in Diplex or Quadruplex Telegraphs, of which the following is a specification.

My invention relates to certain improvements in the apparatus which has heretofore been employed at the receiving-station for the reception of two independent sets of signals simultaneously transmitted in the same direction over one line-wire. In the system 'now commonly in use for this purpose one message is received upon a polarized relay, responsive only to variations in the polarity of line-current, and the second message is received upon a neutral relay responding only to variations in strength of line-current. If, now, for an in terval, a strength of current be on the line for actuating the neutral relay, and during such time a reversal in polarity thereof be effected, a momentary cessation of magnetism in the neutral relay will result,whereupon its armature will recede from its attracted position and tend to produce a false signal. To practically avoid this difficulty, I propose to entirely dispense with the neutral relay and employ only a single'polarized relay, which, responsive to variations in polarity and in strength of line current, either or both, shall actuate two sounding or recording instruments, one of whichsay the first-shall be actuated by said relay when responding to variations in polarity of main-line current, and the second of which shall be actuated by said relay when responsive to changes in strength of main-line current. The successful operation of a relay of this character depends, to a great extent, in placing the contact-points of the local circuits operated thereby in a certain relative position to each other and to the armature. For instance, in a transmitting system where the normal strength of current is the weaker, the armature may normally rest upon a rear stop. ()ne local circuit would be operated by an increase of this normal strength, and the armature would take its position against a front stop. If the polarity of this current be reversed, to operate (No model.)

the second local circuit during the interval of cessation of magnetism due to such reversal, a backward movement of the armature will be initiated. For this reason I place the contact stop for operating the local circuit so controlled by reversals in the rear of the contact-stop of the local circuit operated by an increase of current-strength, the idea being to so arrange the local-circuit connections of the relay that the position of the local contact-stop for operating that sounder responsive to reversals of line-current shall be in a direction relatively to the position of the contactstop for operating the sounder responsive to variations in strength of line-current, which is indicated by the direction of movement initiated by the armature during such reversals. To accomplish this obj ect,Iemploya polarized relay, which may be of the ordinary Siemens type, having an armature-bar pivoted upon a universal joint, affording a capacity of movement in any axial plane of said armature.

' Upon the free extremity of the armature bar a metal contact-disk free to rotate is pivoted, the plane of the disk and the longitudinal axis of the armature-bar being at right angles. In a oircle'surrounding the periphery of the disk are four adjustable contact-stops. Two of said stops are insulated and two are electrical contact-stops. The latter are respectively the terminals of two local circuits. Each circuit embraces the coils of a sounding or recording instrument. The armature-bar is common to both the other terminals of said circuits. The space or are between any two successive stops forms a rest, wherein the contact-disk may lodge under the influence of a predetermined condition of line-current. This form of receiving-instrument is applicable to either the three-current system or the four-current system of transmission. For the purpose of explaining my device I have chosen the latter, in which the succession of currents are strong positive, strong negative, weak positive, weak negative. Normally the full strength of current, say of positive polarity, is upon the line, and the armature-bar is drawn to its extreme left front contact, the location of the two insulated contact-stops being such that the contact-disk rests between them, and both local circuits are open. If the normal strength be now decreased without reversal, the contactdisk is carried into a position between the first insulated contact-stop and the first electrical contact-stop, thus completing one of the local. circuits. If the normal strength of current is reversed, the contact-disk is carried to its right front contact and takes position between the second insulated contactstop and the second electrical contactstop, whereby the other local circuit is closed. the normal current be reversed and decreased, the contact-disk is carried into a position between the two electrical stops, and both local circuits are closed. Thus one local sounder responds only to reversals and the second local sounder responds only to variations in strength of main-line current.

In the accompanying drawings, Figure 1.

shows my improved receiving instrument; also a main battery and transmitting-instruments, with connections adapted thereto, in a normal position. Figs. 1, 2, 3, and 4. are plan views of the contact-disk and local-circuit connections when under the influence of various conditions of main-line current.

R is a polarized relay, which may be of the ordinary Siemens type, having an armature, A, pivoted at 0 to the movable support O,and capable of moving to and fro between the polepieces of the relay-magnet. The movable support 0 is pivoted to lugs at p p, permitting a motion to and fro in the direction of the longitudinal axis of the magnets. A spiral spring, 8, tends to retract armature A with sufficient force to hold it on its back stop when no current is on the line. Upon the free end of armature A is pivoted a disk of metal, 10, preferably platinum, and free to rotate. Its plane is at right angles to the longitudinal axis of said armature. In the circumference of a circle surrounding the periphery of the disk,and in the same plane therewith, are four adjustable stops. a is an electrical contact-stop,and forms the back contact for disk 10. cis an insulated stop, and forms the front contact of disk '10. (l is an insulated stop, and b is an electrical contact-stop. The two latter stops should preferably be placed opposite each other in a line at right angles to a line joining stops (4 and c, and the point of intersection of such lines should be distant from a about the space of half theradius of disk 10, the object being to so position I) and d that a latitudinal movement imparted to armature A by an increased strength of current of either polarity will cause disk a to roll around the end of b or d and break contact with stop a.

S and S are two sounders or recording-instruments. L B and L B are local batteries for operating S and S, respectively. One terminal of the local circuit of sounders S is con nected to electrical contact-stop b by wire a. The other end is connected to armature A. One end of local circuit of sounder S is 0011- nected to electrical contact-stop a by wire 1. The other end thereof is connected to the armature by wire The armature-bar is com mon to both circuits.

The transmitting apparatus and connections are well known. The main battery is in two sections, B and 3 B, preferably in the proportions of l to 3. K is a key or transmitter for reversing the polarity of the current passing to line. K is a key or transmitter for varying the strength of the current sent to line.

The receiving apparatus adapts itself to the four possible conditions of line-current, and the operation of the device may be described as follows: Transmitters K and .K both open; current to line at 13; armature A assumes a left front position, and disk rests between stops 0 and d, Fig. 1"; both local circuits are open. Transmitter K closed, Kcpen current to line 4: B; armature A assumes a right front contact; disk rests between stops Z) and c, Fig. 2; local circuit of sounder S is closed via the elements A, 3, S, L 13, 4, I), and 'w; sounder S responds. Transmitter K closed, K open current to line L; armature A assumes a rear left position and disk 10 rests between stops c and d, Fig. 3; local circuit of sounder S is closed m'a elements a, 1, L B, S, 2, A, and w,- sounder S responds. Transmitters K and K both closed; current to line B; armature A assumes a rear right posi tion; disk 10 rests between stops at and b, Fig. l; both local circuits are closed; both sounders respond. It will thus be seen that sounder S responds only to the operation of transmitter K, and that sounder S responds only to the operation of transmitter K.

It is to be observed that if, while transmit ter K is closed and the disk 20 is in the position shown in Fig. 3, a reversal occur by the operation of transmitter K, the momentary cessation of magnetism in the coils of the relay R will tend to allow armature A to drop back; but this direction of movement so ini' tiated is continued by the reversal and causes no false movement of disk 10. A reversal of the entire battery by the operation of trans mitterli is found to cause no false signal, the movement of disk w in practice being performed too quickly to allow sounder S to respond. The armature A has a resultant movement, the components of which are, first, the

back movement toward a upon cessation of magnetism due to the reversal of a strong current; and, second, the movement of the armature due to the positive action of the increased current. The resultant movement is in a direction toward contact-stop b, with which it is desired to make connection rather than toward contact a, connection with which would cause a false signal. The cessation of magnetism, therefore, upon reversal of a strong cun rent only tends to slightly divert the armature away from a straight path of movement to ward the contact with which it is desired to make connection.

The limit of movement of disk 20, as indicated in Figs. 1 to 4, is too great, being exaggerated to facilitate description, and in practice should be limited to a smaller space.

Any of the well-known methods for duplex telegraphy may be applied to the system of duplex telegraphy here described'to form a quadruplex system.

WVhat I claim, and desire to secure by Letters Patent, is-

1. An electro magnetic receiving -instrument having a single armature pivoted upon a universal joint, and capable of taking four contact positions, respectively, located in different radial planes with respect to the central position of the armature and against contactpoints.

2. An electro magnetic receivinginstrument responsive to variations in the polarity and in the strength of line-current, either or both, provided with one armature whichis pivoted upon a universal joint, and in connection with two local circuits, and four fixed stops so located as to circumscribe the movements of said armature, substantially as described.

I 3. An electromagnetic receiving-instrument responsive to variations in the polarity and in the strength of line-current, either or both, provided with one armature capable of taking four positions, and pivoted upon a universal joint, substantially as described.

4. An electro magnetic receiving-instrument responsive to variations in the polarity and in the strength of line-current, either or both, having one armature upon a universal joint provided with three working-contacts and one resting-contact.

5. A receiving instrument responsive to changes in the polarity and in the strength of main-line current, either or both, having one armature, and a rotating local-circuit contactpoint, in combination with a main battery or 0 batteries, and two keys or transmitters, one of which transmitters controls the polarity of the line-current and the other the strength of line-current.

6. A receiving instrument responsive to 5 changes in the polarity and in the strength of line-current, either or both, having one armature, and a rotating local-circuit contactpoint, in combination with means for generating an electric current, and two keys ortrans- 5o mitters, one of whichsaythe first-when 0perated controls the strength of main-line current, the polarity of which is varied by the operation of the second key or transmitter.

7. In a duplex-telegraph relay, the co1i1bination of an armature-bar, anda series of contactstops surrounding said armature, two of .which stops, respectively, form the poles of two local circuits, the whole being arranged, as shown, whereby the resultant of the move- 60 ment of the armature upon the cessation of magnetism due to a current reversal and the movement of the armature due to the direct action of the reversed current shall be in direction toward the contact for making the desired signal, and away from the contact by which, if connection were made therewith, a false signal would be caused.

8. The receivinginstrument, R, having armature A, disk 10, and stops at b c d, with their 70 local-circuit connections, substantially as de scribed.

GERRITT SMITH. WVitness'es:

VVM. l3. VANSIZE, I WM. ARNOUX. 

